1914] Dickerson: Fauna of the Martinez Eocene of California 147 



is flat or slightly convex. Surface of body whorl marked by ten to 

 twelve spiral lines with interspaces twice as wide; oblique lines of 

 growth are found also. Canal slender, very long, straight^ 



Dimensions. Length of spire, 12 mm. ; length of body whorl from 

 suture to constriction, 7 mm. ; width of body whorl, 8 mm. 



Occurrence. The type specimen was found by Dr. C. E. Weaver 

 at University of California Locality 790, Lower Lake. 



Fusus dumblei resembles F. mathewsonii Gabb in its marked angu- 

 lation, but it lacks the double angulation on the lower whorls and it 

 is far less robust than F. mathewsonii. This is the only Fusus thus 

 far reported from the Martinez of Lower Lake. 



Named in honor of Professor E. T. Dumble, Consulting Geologist, 

 Southern Pacific Company. 



OLIVELLA CLAYTONENSIS, n. sp. 



Plate 16, figure 7 



Small, spire very low ; whorls four, suture covered ; surface marked 

 faintly by transverse growth lines, mouth not exposed. Outer lip 

 thickened. 



Dimensions. Height, 8 mm. ; width of body whorl, 4 mm. 



Occurrence. University of California Locality 1543. 



This species differs from Olivella mathewsonii in height of spire. 



TUEEIS LOUDERBACKI, n. sp. 

 Plate 16, figures 9a, 9& 



Shell fusiform, with high spire which is nearly equal in length to 

 the body whorl; eight whorls marked by twelve rounded nodes. The 

 slightly concave space above the shoulder of the whorl slopes steeply 

 from the impressed linear suture. In the whorls of the spire this 

 space is twice as lorg as the nodose convex space below the angle. 

 Fine rounded spiral lines decorate the whorls. Growth lines indicate 

 a sinus at angle. Outer lip simple; inner lip incrusted; canal long, 

 straight. 



Dimensions. Length of nearly complete specimen, 35 mm. ; width 

 of body whorl, 13 mm. 



Occurrence. University of California Locality 1540, Trocho- 

 cyathus zitteli zone north of Mount Diablo, and same zone at type 

 locality. 



